Strain-insulator.



nu rient No, 881,064, Spa

Application filed Jim cation Our invention relates to strain insulators for electric lines and it has for its object to provide a device of this characterthat shall be simple and durable in construcvention.

' Referring to the drawing, the insulator illustrated, comprises a rod or tube 1, preferably of iron, a collar 2 which is fitted onto the rod 1, an insulating tube 3, an eye ring 4 and an insulating envelop or casi g 5 of a suitable composition that may be molde desired shape. i

The insulating tube 3 is of materially greater length than the collar 2 over which it is fitted, the collar being locatedsubstantially in the center of the tu e. The eye ring comprises a collar portion 6 which is fitted over the insulating tube 3 directly outside the col ar 2, and a projection 7 the extremity of which may be formed into a ring 8, asillustrated, or may be caused to assume any other convenient shape, such as a hook, to which a line conductor, a cable or a rope may be attached'.

Although the insulating tube 3 is relatively thin so that the direct distance between the inner collar 2 and the uter'collar 6 is inconsiderable, if it is formed oi compressed layers of sheet fabric, mica and varnish or shellac, it will resist relatively high voltage strains, and the possibility of electrical leakage around its ends is reduced to a minimum by reason of the length of the tube.

In order to protect the insulator from the Weather and to'still further guard against electrical leakage, the envelop or casing 5 or molded insulating material, is provided, which completely surrounds the exposed por- 1; [ir'iLBOi Gr, OF WlLKlNSBURG, PENN- Patenteol July 23, 190?.

tions of the insulating tube 3 both inside and outside,

and a corrugated sleeve projection 9 surrounds the pro jection 7.

The portions of the molded insulator which extend inside the tube 3 are relatively thin so that they avoid engagement with the metal rod or tube 1. way, it is possible to remove the coi -u 2 from the rod without destroying the molded insulator and, furthermore, bending strains to which the or tube 1 may be subjected, will not affect the envelop 5. y

We desire that variations which d not depart lrom the spirit of our invention shall be included within its scope.

We claim as our invention:

1. Au insulator comprising an inner ring, an insulating tube of materially greater length then the ring and fitted over it. an outer ring 'tted over the tube around the first ringand having a strain projection, and a molded insulut r casing surround. the exposed surface of the tube and the joceut )0 on the strain projection, and having an i1 ernar diameter nter than that of the inner ring.

2. A strain insulator comprisin collar closely fitting the middle p ing tube ritted over his collar an ends, a rim: closely ng the middle lating tube and having a looped projection and I insulating casing for the ring and the insulating 1 internal diameter of which is greater. than tlmt'of the collar.

1 strain insulator comprising a relatively long insulating tube. a collar located in the middle of the tube and closely fitted therein, an eye band fitted around the middle of the tube, and a molded insulating sheath which sur rounds the eye band and the exposed portions oi" the tube and engages and is or" less internal diameter than the collar.

A strain insulator comprising, :1 metal cylindrical member, a collar surrounding said member, an insulating tube of materially greater length than the collar and fitted thereon, a strain ring fitted over the tube around the collar, and a molded insulator which surrounds the exposed parts of the insulating tube and makes no contact with the I in this 

